Endometriosis

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INTRODUCTION — The normal tissue that lines the uterus and bleeds during the menstrual period is called the endometrium. Endometriosis is a noncancerous disorder in which tissue that is similar to the endometrium develops outside of the uterus. Typically this occurs in the pelvis, but it may occur in virtually any part of the body.

The most common locations for endometriosis are: the outer surface of the ovaries, peritoneum (the tissue that lines the abdomen) and peritoneal structures (the area behind the uterus and the various ligaments that hold the uterus in place), uterus, fallopian tubes, bowel, and bladder. Most women have endometriosis in more than one location.

RISK FACTORS — the disease can only be diagnosed with a biopsy of lesions seen during surgery. Therefore, women who have no symptoms and never have surgery may not know that they are affected. The growth and function of endometriosis depends upon stimulation from Estrogen and Progesterone, which are produced by the ovaries in women who menstruate.

Risk factors for developing endometriosis include:

• No pregnancies
• Endometriosis in a woman's mother (7 percent chance)
• Short menstrual cycles (<27 days) with prolonged flow (>8 days) (2 percent chance)
• Partial or complete obstruction of normal menstrual flow (eg, from uterine abnormalities such as a tight cervical opening or vaginal septa [band of tissue] blocking the flow of menses)
• White or Asian race

CAUSES — The cause of endometriosis is not known, but several theories have been suggested.

• Retrograde menstruation is a theory that menstrual blood and tissue flows backwards from the uterus, through the fallopian tubes and into the pelvis.This theory was proposed because women with a partial or complete obstruction of the uterus or cervix that prevents normal menstrual flow are more likely to have endometriosis. This is presumably because menstrual blood and tissue are more likely to flow backwards. Retrograde menstruation has been observed during surgery. The endometrial tissue shed during a menstrual period is able to grow when "planted" in the pelvis.                                                                                                                                                                               

• Endometrial tissue from the uterus may be transported through blood and lymphatic vessels to sites elsewhere in the body, including the pelvis.
• Changes in the immune system allow endometrial tissue outside of the uterus to grow and develop.
• Coelomic metaplasia is the concept that the cells from lining of the abdomen and surface of the ovaries can change into endometrial tissue with certain stimuli, such as irritation from retrograde menstruation or infection.

SIGNS AND SYMPTOMS

Pain — For many women, severe pelvic pain is the main symptom of endometriosis. Pelvic pain usually occurs just before or during menses or during or after sex. Other symptoms may include pain during bowel movements, spotting before the menstrual period, frequent or heavy uterine bleeding, and pain during urination. Some women have pelvic soreness or pain in the lower back and legs that is aggravated during menses or intercourse.

Pelvic pain is probably the result of bleeding from areas of endometriosis and release of substances that cause pain. Endometriosis implants respond to the hormonal changes that occur during the menstrual cycle, similar to the normal endometrium. Thus, at the end of the menstrual cycle, small amounts of endometrial tissue are shed and bleeding in the pelvis occurs.

Endometriomas (chocolate cysts) — Endometriomas are areas of endometriosis that are large enough to be considered a mass or growth. They are usually filled with old blood that resembles chocolate syrup; thus, they are sometimes called chocolate cysts. Endometriomas may be seen during a pelvic ultrasound, although only surgery can confirm that the mass is an endometrioma.

Pelvic examination — During a pelvic examination, a healthcare provider may feel thickening of, or nodules on, pelvic structures, an adnexal mass (a mass in the area of the ovary), or fixed or distorted pelvic organs, which suggests the presence of endometriosis. However, since these signs and symptoms are present in a variety of disorders, the diagnosis and stage (severity) of endometriosis can only be made with certainty by viewing the implants (small areas of endometriosis) during surgery, with either laparoscopy or laparotomy.

There are no blood tests or imaging tests that can make a definitive diagnosis of endometriosis.

Surgical evaluation — Laparoscopy and laparotomy are surgical procedures that are commonly used to diagnose and treat endometriosis. Both procedures are usually done in an operating room after the woman has received general anesthesia to induce sleep and prevent pain. After laparoscopy most women go home the same day. After laparotomy most women go home after spending one to three nights in the hospital.

At surgery, endometriosis appears as small blue, purple, or red implants. Scar tissue (adhesions) and/or an ovarian cyst may also be noted.

TREATMENT: 

There are several treatment options for women with endometriosis:

• No therapy
• Pain medication
• Birth control pills
• Other forms of hormonal therapy
• Surgery
• A combination of therapies

The treatment strategy depends upon whether the woman's major concern is pain, infertility, or a pelvic mass.

Women with minimal disease or who are near menopause and have no troubling symptoms may choose to have no treatment. Near menopause, endometriosis may regress without treatment because the ovaries produce lower levels of estrogen, which decreases stimulation of the implants. Young women with minimal disease may consider taking a hormonal birth control treatment to prevent unplanned pregnancy and progression of disease.

Endometriosis progresses slowly, over years, and resolves after menopause. Most women with endometriosis will get relief of pain from a medication, after pregnancy, or after menopause; some women will be helped only by surgery. Removal of the ovaries almost always provides excellent pain relief, making this an option for women who do not wish to have children.

Some women with endometriosis will have difficulty becoming pregnant, especially those who have severe disease and extensive adhesions. However, most women can achieve pregnancy after medical or surgical therapy or with fertility enhancing drugs or procedures (eg, in vitro fertilization).

Pelvic pain — There are two options for treating pelvic pain caused by endometriosis: medications and surgery.

• Medications — An advantage of using medications to treat endometriosis is that it treats all implants, not just those seen during surgery. Disadvantages of medical therapy include the inability to treat existing scar tissue or endometriomas. Medications may have side effects, including prevention of pregnancy (if drugs that suppress ovulation are used), and pain often recurs when medical therapy is stopped.
• Surgery — If surgery (laparoscopy) is performed to diagnose endometriosis, endometrial implants and scar tissue are usually removed, which may relieve pain temporarily. However, the disease and pain tend to recur unless the uterus and ovaries are removed. Recurrent or persistent pain after surgery is usually treated with medication. In addition, surgery has potential risks, some of which include damage to pelvic organs and formation of scar tissue. Studies have not determined the best medical therapy for treating pelvic pain, and no medical therapy has been proven to improve the chance of becoming pregnant in the future.

Nonsteroidal anti-inflammatory drugs — Nonsteroidal anti-inflammatory drugs (NSAIDs, eg, Ibuprofen, Naproxen sodium) may be useful in relieving mild pain.

Serious side effects from NSAIDs, although uncommon, include gastrointestinal pain and bleeding, kidney problems, and worsening high blood pressure.

Hormonal birth control treatments — Birth control pills, patches, and the vaginal ring contain both estrogen and progestin, which cause the endometrial lining and endometriosis implants to shrink. There is no effect on scar tissue or endometriomas.

Gonadotropin releasing hormone agonists — Gonadotropin releasing hormone (GnRH) agonists work by temporarily stopping the ovaries from producing estrogen, thereby causing a temporary menopause. The lack of estrogen causes the endometriosis implants to shrink and reduces pain in over 80 percent of women. The drugs may be given as a nasal spray, implant, or injection.

The full dose of a GnRH agonist may be taken for up to six months; a longer course is not usually recommended due to the risk of bone thinning. Side effects of GnRH agonists can include headaches (in 20 percent of women, especially those with a history of migraine) and the signs and symptoms of menopause (lack of menstrual bleeding, hot flashes, vaginal dryness, decreased libido, insomnia, and loss of bone density).

Five years after completing GnRH agonist treatment, many women will again have pain (37 of women with mild disease and 74 percent of women with severe disease).

Progestins — Progestins  may be recommended for women who do not get pain relief from or who cannot take a birth control pill (eg, smokers). These medications cause the endometrial lining and endometriosis implants to shrink, and usually cause the menstrual periods to temporarily stop.

Side effects are common and may include: bloating, weight gain, irregular uterine bleeding, and rarely, worsened depression. Women who take injections of long-acting Medroxyprogesterone acetate (eg, Depo-Provera®) may not have a menstrual period for six to twelve months after stopping the treatment. Therefore, this drug may not be the best choice for women planning pregnancy in the near future.

Danazol — Danazol is a medication that increases the level of androgens (male type hormone) and decreases the level of estrogen. This temporarily stops the menstrual period by inhibiting ovulation and ovarian production of estrogen and by shrinking the endometrium.

Side effects may include weight gain, edema, decreased breast size, acne, oily skin, hirsutism (male pattern hair growth), deepening of the voice, headache, hot flashes, changes in libido, and mood changes. All of these changes are reversible, except for voice changes; however, return to normal may take many months.

Danazol is not recommended for women with certain types of liver, kidney, and heart disease because these disorders may worsen. Women who could become pregnant must use a nonhormonal form of birth control (eg, condoms) while taking danazol because of a serious risk of birth defects if danazol is used during pregnancy.

SURGERY- Surgery is an option when medications have failed to improve pain or if there is severe disease (scarring, endometriomas, involvement of the bowel or bladder) that is unlikely to respond to medications alone. The goal of surgery is to eliminate as many implants and adhesions as possible.

More than 80 percent of women who have surgery have relief of pain, although there is a 40 risk of recurrent pain within 10 years. Women who have surgery avoid the possible side effects of medication and may have improved fertility. However, surgery has some potential risks, including damage to pelvic organs, development of new adhesions (scar tissue), bleeding, and infection.

Pelvic mass — In a woman with endometriosis, a pelvic mass could be an endometrioma (chocolate cyst), a combination of scarring and normal pelvic organs, or a mass unrelated to the disease. Surgery is the best way to make a definite diagnosis and remove the mass. Medical therapy is not effective.

Infertility— Endometriosis sometimes interferes with the ability to become pregnant. Reduced fertility may develop because of adhesions that develop between the ovaries and fallopian tubes or as a result of substances produced by endometriosis implants, which impair normal ovulation, fertilization, and implantation. The treatment of infertility caused by endometriosis includes a combination of observation, surgery, use of medications that enhance ovulation combined with intrauterine insemination, or in vitro fertilization (IVF).

The ideal infertility treatment for women with mild to moderate endometriosis is surgical removal (burning or cutting) of endometriosis implants.

PREVENTION — There is no proven way to prevent endometriosis. Reducing the number of periods and amount of bleeding during the menstrual period may reduce the risk. Having one or more pregnancies or using a hormonal birth control (eg, birth control pills) may be of benefit.

SUMMARY

• Endometriosis is a common condition in women. Its name is based on the endometrium, which is the tissue inside the uterus. During a woman's monthly period, the endometrium sheds and bleeds. With endometriosis, tissues that are similar to the endometrium grow outside the uterus. These growths also bleed during a woman's monthly period. The condition is not related to cancer.
• The cause of endometriosis is not known. Women whose mother, sister, or aunt had endometriosis have a higher chance of developing it.
• The most common symptom of endometriosis is pain. Pain may occur in the abdomen, lower back, or pelvis, and is usually worst before and during a woman's monthly period. Some women also have pain during sex.
• Surgery is needed to be certain of the diagnosis of endometriosis. Surgery is not always performed if endometriosis is likely and pain improves with medical treatment.
• There are many treatments for endometriosis. For most women, the first option is to use a medication to reduce pain and shrink the abnormal growths. Surgery may be the best choice for women with severe disease or pain that does not improve with medications.

Endometriosis can cause difficulty becoming pregnant (infertility). If endometriosis is mild, surgery to remove the abnormal growths can treat infertility. Some women also need to use infertility medications or procedures to become pregnant (eg, in vitro fertilization or IVF).